The invention relates to a plug connector for a coaxial cable, the said plug connector having a plug-in side and a conductor-connecting side and consisting of a sleeve-shaped, metal plug-in part into which an insulating body is pushed, in the process of which a contact element is introduced into the said insulating body.
The purpose of the invention is to achieve a plug connection between a plug connector for coaxial cables and a corresponding counter-plug or direct to a suitably contoured printed circuit board rim on a printed circuit board, wherein, however, high electrical reliability of plugging-in is to be guaranteed.
From EP 0 848 459 A2, a line plug connector for transmitting electrical energy between a coaxial cable and a printed circuit board is known, in which a printed circuit board is provided, in the region of its rim, with a number of elongated slots by means of which tongues are constructed whose flanks are subsequently metallised, and wherein a line plug connector of suitable design brings about an electrical contact between the metallised flanks and the electrical components of the plug part on the cable.
The problem with plug connectors of this type lies in achieving simple plug assembly with reliable screening and good electrical coupling between a plug-in contact and the signal-conveying electrical conductor of the coaxial cable, in order to guarantee interference-free signal transmission.
The underlying object of the invention is therefore to construct a plug connector of the initially mentioned type in such a way that easy and thereby cost-effective fitting with optimum screening and signal-conveyance, and also reliable electrical plugging-in of coaxial cables, are made possible by the use of a few simple components.
This object is achieved through the fact that the insulating body is provided, in a partial region, with tongues which are formed by longitudinal slots and which point outwards, that a number of central bores which are arranged in a row and differ in diameter are provided in the insulating body, that the ends of the tongues are provided, on their side which points towards the interior of the insulating body, with conical or widening gradations, that the middle conductor of the coaxial cable is introduced into a receiving bore in the contact element, and that the insulating body is pushed into the sleeve-shaped plug-in part, in the process of which the outwardly pointing tongues are pressed together and the gradations exert a pressure on the insulation of the middle conductor.
Provision is preferably made for the plug connector to be provided with an insulating body which is introduced into a sleeve-shaped metal plug-in part, is capable of centrally receiving an electrical contact element and connects a central electrical middle conductor of a coaxial cable to the said contact element.
Provision is also advantageously made for first of all providing a tension-relieving system for the central electrical middle conductor, and also for achieving further relief of tension between the sheath of the coaxial cable and the plug-in part, by means of crimping onto the sleeve-shaped plug-in part.
In its interior, the insulating body, which is constructed as an elongated round body, has a number of graduated diameters, while outwardly pointing tongues formed by longitudinal slots extend from a head part, which is segregated by a circumferential annular groove, as far as the end of the said insulating body.
The differently graduated bores in the interior of the insulating body are preferably coordinated with the outer diameters, which receive them, of the electrical contact element and of the coaxial cable.
Under these circumstances, gradations, which are forced into the insulation when the tongues are pressed together, are preferably provided in the insulating body in the region of the insulation of the electrical middle conductor.
For the secure retention and centering of the electrical contact element, the latter is advantageously provided with two thickened portions which are disposed in a spaced-apart manner and which are forced against the wall of the inner bore of the insulating body.
A conical widened portion of the inner diameter is additionally provided, which is, however, narrowed in such a way, when the tongues are pressed together, that the inner wall of the insulating body rests directly on the outer wall of the electrical contact element in this region and thus also exerts a pressure on the electrical middle conductor.
According to the preferred form of embodiment, provision is made for making reliable electrical contact with the screen by means of a lamellar spring. To that end, an annular lamellar-spring arrangement with lamellae which are disposed so as to be inclined by about 45xc2x0 in relation to the perpendicular is pressed tightly into the front plug-in region of the plug-in part.
In this way, the plug connector can be plugged onto any matching counter-plug and also directly onto a printed circuit board which is suitably provided for that purpose.
The advantages obtained with the aid of the invention consist, in particular, in the fact that, as a result of this design, very simple handling is achieved during fitting, in the process of which the contact element is first of all pushed onto the middle conductor, which has been stripped of insulation, of a coaxial cable, the two parts are introduced into the insulating body, and these are inserted in turn, almost without any force, in the sleeve-shaped plug-in part and are finally connected to one another with the aid of a crimping operation in the region of the screen of the coaxial cable.
Advantageous refinements of the invention are indicated in claims 2 to 7.